Amazon Linux 2 : kernel (ALAS-2023-1987)

high Nessus Plugin ID 173233

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of kernel installed on the remote host is prior to 4.14.309-231.529. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2023-1987 advisory.

- A speculative pointer dereference problem exists in the Linux Kernel on the do_prlimit() function. The resource argument value is controlled and is used in pointer arithmetic for the 'rlim' variable and can be used to leak the contents. We recommend upgrading past version 6.1.8 or commit 739790605705ddcf18f21782b9c99ad7d53a8c11 (CVE-2023-0458)

- Use After Free vulnerability in Linux kernel traffic control index filter (tcindex) allows Privilege Escalation. The imperfect hash area can be updated while packets are traversing, which will cause a use- after-free when 'tcf_exts_exec()' is called with the destroyed tcf_ext. A local attacker user can use this vulnerability to elevate its privileges to root. This issue affects Linux Kernel: from 4.14 before git commit ee059170b1f7e94e55fa6cadee544e176a6e59c2. (CVE-2023-1281)

- A use-after-free vulnerability in the Linux Kernel traffic control index filter (tcindex) can be exploited to achieve local privilege escalation. The tcindex_delete function which does not properly deactivate filters in case of a perfect hashes while deleting the underlying structure which can later lead to double freeing the structure. A local attacker user can use this vulnerability to elevate its privileges to root.
We recommend upgrading past commit 8c710f75256bb3cf05ac7b1672c82b92c43f3d28. (CVE-2023-1829)

- The Linux kernel allows userspace processes to enable mitigations by calling prctl with PR_SET_SPECULATION_CTRL which disables the speculation feature as well as by using seccomp. We had noticed that on VMs of at least one major cloud provider, the kernel still left the victim process exposed to attacks in some cases even after enabling the spectre-BTI mitigation with prctl. The same behavior can be observed on a bare-metal machine when forcing the mitigation to IBRS on boot command line. This happened because when plain IBRS was enabled (not enhanced IBRS), the kernel had some logic that determined that STIBP was not needed. The IBRS bit implicitly protects against cross-thread branch target injection.
However, with legacy IBRS, the IBRS bit was cleared on returning to userspace, due to performance reasons, which disabled the implicit STIBP and left userspace threads vulnerable to cross-thread branch target injection against which STIBP protects. (CVE-2023-1998)

- A use-after-free vulnerability was found in iscsi_sw_tcp_session_create in drivers/scsi/iscsi_tcp.c in SCSI sub-component in the Linux Kernel. In this flaw an attacker could leak kernel internal information.
(CVE-2023-2162)

- In the Linux kernel before 6.1.13, there is a double free in net/mpls/af_mpls.c upon an allocation failure (for registering the sysctl table under a new location) during the renaming of a device. (CVE-2023-26545)

- A use after free flaw was found in hfsplus_put_super in fs/hfsplus/super.c in the Linux Kernel. This flaw could allow a local user to cause a denial of service problem. (CVE-2023-2985)

- A flaw was found in the Framebuffer Console (fbcon) in the Linux Kernel. When providing font->width and font->height greater than 32 to fbcon_set_font, since there are no checks in place, a shift-out-of-bounds occurs leading to undefined behavior and possible denial of service. (CVE-2023-3161)

- An issue was discovered in drivers/usb/storage/ene_ub6250.c for the ENE UB6250 reader driver in the Linux kernel before 6.2.5. An object could potentially extend beyond the end of an allocation. (CVE-2023-45862)

- A memory leak problem was found in ctnetlink_create_conntrack in net/netfilter/nf_conntrack_netlink.c in the Linux Kernel. This issue may allow a local attacker with CAP_NET_ADMIN privileges to cause a denial of service (DoS) attack due to a refcount overflow. (CVE-2023-7192)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2023-1987.html

https://alas.aws.amazon.com/faqs.html

https://alas.aws.amazon.com/cve/html/CVE-2023-0458.html

https://alas.aws.amazon.com/cve/html/CVE-2023-1281.html

https://alas.aws.amazon.com/cve/html/CVE-2023-1829.html

https://alas.aws.amazon.com/cve/html/CVE-2023-1998.html

https://alas.aws.amazon.com/cve/html/CVE-2023-2162.html

https://alas.aws.amazon.com/cve/html/CVE-2023-26545.html

https://alas.aws.amazon.com/cve/html/CVE-2023-2985.html

https://alas.aws.amazon.com/cve/html/CVE-2023-3161.html

https://alas.aws.amazon.com/cve/html/CVE-2023-45862.html

https://alas.aws.amazon.com/cve/html/CVE-2023-7192.html

Plugin Details

Severity: High

ID: 173233

File Name: al2_ALAS-2023-1987.nasl

Version: 1.7

Type: local

Agent: unix

Published: 3/22/2023

Updated: 1/23/2024

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2023-1829

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-livepatch-4.14.309-231.529, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, p-cpe:/a:amazon:linux:python-perf, p-cpe:/a:amazon:linux:python-perf-debuginfo, cpe:/o:amazon:linux:2

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/17/2023

Vulnerability Publication Date: 2/25/2023

Reference Information

CVE: CVE-2023-0458, CVE-2023-1281, CVE-2023-1829, CVE-2023-1998, CVE-2023-2162, CVE-2023-26545, CVE-2023-2985, CVE-2023-3161, CVE-2023-45862, CVE-2023-7192